Intermittent Naltrexone Among Polysubstance Users (Project iN)

This study has been completed.

Sponsor:

University of California, San Francisco

ClinicalTrials.gov Identifier:

NCT01723384

First Posted: November 7, 2012

Last Update Posted: December 16, 2014

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government.
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Naltrexone, a µ-opioid receptor antagonist, is a promising agent for methamphetamine-using and binge-drinking men who have sex with men (MSM). Naltrexone has shown efficacy in reducing relapse to amphetamines and is FDA-approved for alcohol dependence. Oral naltrexone is inexpensive and has few toxicities but the standard daily regimen for naltrexone is problematic as patients forget to take the medication. Given the challenges in daily dosing, alternate regimen schedules have been proposed to increase efficacy and expand the population that may benefit from this pharmacologic agent. One approach is intermittent targeted administration of naltrexone, whereby individuals take the medication as-needed in anticipation of substance use or during periods of craving. Administration of naltrexone prior to exposure to amphetamines significantly attenuates craving and targeted naltrexone has shown efficacy in reducing heavy alcohol use. However, there have been no studies assessing intermittent targeted dosing of naltrexone among methamphetamine-using and binge-drinking MSM. Polysubstance use patterns are common among MSM, and studies among those who abuse more than one substance are urgently needed. The aims of this study are to determine whether targeted dosing of naltrexone is feasible, tolerable and acceptable among non-dependent methamphetamine-using and binge-drinking MSM.

Intermittent oral naltrexone to be taken on an as-needed basis for 8 weeks.

Drug: Intermittent Oral Naltrexone

Placebo Comparator: Placebo

Intermittent oral placebo to be taken on an as-needed basis for 8 weeks

Drug: Placebo

Eligibility

Information from the National Library of Medicine

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Ages Eligible for Study:

18 Years to 70 Years (Adult, Senior)

Sexes Eligible for Study:

Male

Accepts Healthy Volunteers:

Yes

Criteria

Inclusion Criteria:

male gender or transgender male-to-female

self-reported anal sex with men in the prior six months while under the influence of meth and/or alcohol

self-reported meth use at least bi-weekly in the prior three months

at least weekly binge drinking (five or more drinks on a single drinking session) in the prior three months

4) interested in reducing meth use and/or binge drinking 5) HIV-negative by rapid test or medical record of HIV infection 6) no current acute illnesses requiring prolonged medical care 7) no chronic illnesses that are likely to progress clinically during trial participation 8) able and willing to provide informed consent and adhere to visit schedule 9) age 18-70 years 10) baseline complete blood count (CBC), total protein, albumin, glucose, alkaline phosphatase, creatinine, blood urea nitrogen (BUN), and electrolytes without clinically significant abnormalities as determined by study clinician in conjunction with symptoms, physical exam, and medical history

Exclusion Criteria:

any psychiatric (e.g., depression with suicidal ideation) or medical condition that would preclude safe participation in the protocol

known allergy or previous adverse reaction to naltrexone

current use of or dependence on any opioids or a known medical condition which currently requires or may likely require opioid analgesics